Holdowns of various construction for anchoring multiple studs or posts of framed walls to concrete base have long been known in the art. Examples of such holdowns are disclosed in, for example, U.S. Pat. No. 4,199,908 to Teeters; U.S. Pat. No. 4,924,648 to Gilb et al.; and U.S. Pat. No. 4,995,206 to Colonias et al. Each of these holdowns include an anchoring portion that is set in the concrete base and a pair of spaced, upstanding plates provided with a clearance therebetween to receive a wall post or studs. Screws, throughbolts, nails or other fasteners secure the studs/post in position.
In order to meet building code requirements, each of the holdowns also includes a base member for raising the bottom of the studs/post a set distance above the surface of the concrete base. This is to prevent the studs/post from becoming exposed to water that may rest on the concrete base and would, therefore, otherwise wet the studs/post and cause damage over time. Where wood studs/post are utilized, this is a particularly significant concern.
While the various holdowns developed to date function reasonably well, they do suffer two major shortcomings. Specifically, they are difficult to maintain in alignment and plumb when pouring and spreading concrete. They also do not display the desired strength in tension necessary to resist the uplift caused by overturning due to lateral seismic forces resulting from earthquakes. Accordingly, existing quickset holdowns are not generally utilized for earthquake-resisting shear walls.